Deuteronomy 16:18

Judges and officers. The "officers" ( shoterim , writers) associated with the judges both in the earlier arrangements and in that which was to succeed were secretaries and clerks of court, and acted also as assessors and advisers of the judges. No instruction is given as to the number of judges and officers, or as to the mode of appointing them; nor was this necessary. The former would be determined by the size and population of the place where they were appointed, and the latter would, as a matter of course, follow the method instituted by Moses in the earlier arrangement (see Deuteronomy 1:13-15 ; Exodus 18:21-26 ).